Open Monday through Thursday, 5:30 to 11 p.m.; Friday and Saturday, 5:30 to 11:30 p.m.; Sunday, 1 to 11:00 p.m. AE, CB, MC, V. Reservations. Prices: Main courses $4.95 to $7.95.

HUNGRY people are traditionally suspicious by nature, so when a successful restaurant opens a branch operation, eyes narrow and mouths ready to sneer. There goes the quality, anticipate the cynical tongues, leery of chains even if they have only two links. In Washington, though, we have evidence to allay those fears. Blindfold a diner and dare him to find a difference between the apple pie at one Sholl's cafeteria and the other (or to find a better apple pie in town). Challenge a discriminating palate to make distinctions between the aushak at Bamiyan and its newer branch, Khyber Pass (or to find a more luscious noodle dish within an evening's drive). Clyde's is still Clyde's, even now that they are three.

Worries can be stilled, too, about Columbia Road's El Caribe spawning a Georgetown branch. The conejo a la cazadora is as savory as ever, the ceviche de pescado no less piquant, the black beans not one whit less pungent. All that has happened with the addition of a second El Caribe is that there are now 75 more seats from which to enjoy the wonderful fritadas con llapingachos, a pork casserole with contrasts of unctuous ripe plantains, earthy yucca and camote, salty white cheese patties and a nostril-twitching fragnance of cumin and vinegar. Seventy-five more opportunities are welcome, for even when the dish happens to be served too dry on the chef's day off, it is a delicious, exotic medley.

That's what El Caribe teaches you about Ecudor. It also teaches savory lessons about the Caribbean (roast port), Bolivia (tongue in tomato suace with olives and peppers), Peru (beef with peppers, tomatoes and potatoes) and a great deal about Spain (paellas, seafood casseroles, sherried baby hens, chicken with ham and sausage) and Latin America as a whole. In the Georgetown branch of El Caribe there are 19 main dishes either baked with tempting things or stuffed with delicacies or sauced with aromatics to make choices a struggle. And this is a restaurant where it is a shame not to start with an appetizer and end with a dessert.

Hope for a cool day and begin with ajiaco, a soup of Caribean roots that lets you in on the secret of how much the starchy sweetness of yams can do for a broth. Seviche is more suitable for a summer starter, if you like the sting of hot green peppers. A large portion of raw fish (unfortunately, a little too fibrous) is marinated in lime to transform it to an apparently cooked state, and tossed with plenty of onions, carrots, capers and spirited tiny green olives. For something neither peppery nor heavy, try the shrimp afloat in a buttery garlic sea, or empanadas - their dough more soft than flaky, but their filling tangy with olives and spices ground with the meat and eggs.

El Caribe has long been the champion of fried squid, marinated for flavor and crisped in a frothy batter. Lately, though, the marination seems to have been skipped, for the texture is still delicate, but the taste is bland. A squeeze of lemon helps.

Paella is commonplace by now. At El Caribe you can adventure into seafood casseroles with brandy and tomato or with a tangy pink white wine sauce mingling garlic with the multitude of scents. As with all the main courses, the seafood casseroles are enormous and the ingredients fresh, though the fish suffered the same fibrous flaw found in the seviche The Georgetown El Caribe has four chicken dishes, the newest being a deceptively French-sounding pollo al champignon. The chicken pieces, large and juicy, are presented in a sauce nearly black and fragnant from what seems to be cloves. While the almonds described in the menu were not obvious, there were plenty of mushrooms, and the slight oily sauce demanded to be spooned up to its finish. Another dish specific to the Georgetown location is a New York sirloin big and as rare as requested, bathed in a creamy, brandied brown sauce heady with green peppercorns. It may sound French, but it tastes clearly Latin, and at $8.95 is a Latin bargain.The Georgetown branch also has added French-sounding veal cutlet stuffed with ham and cheese for which I cannot vouch, since I am drawn to more Latin combinations such as lamb with sweet peppers and eye of round stuffed with paprika-spiked Spanish sausage and braised with a brown sauce which reiterates the paprika scent. Round steak is a dry meat, and one should not expect the cooking method to change its character, but its flavor is considerably enhanced by the elaboration.

With all these fragrances and spices, a robust Spanish wine gets along well. And El Caribe has a well-chosen and modestly priced assortment, along with Mexican beer and the biggest "small pitcher" of sangria I have seen, at $4.50. As long as beverages are the subject, one should note the coffee, as fresh and full-bodied a cup as one could wish to end a meal.

But don't end without dessert. Here the flan is dense and smooth and heavily flavored with caramel, quite distinct from its delicate French cousin, creme caramel. A rarer treat is floating island, the caramel-drizzled meringues adrift in a thin pale custard, perhaps too thin but a most pleasant dessert. El Caribe fans know the custardy sponge cake, brazo gitano, but the fruit tarts are new. And rarely is a fruit tart in this city so fine, with a crisp cookie crust and the merest film of soft custard, topped with strawberries and served still crisp, rather than soggy.

Prices are slightly higher at the Georgetown branch - an average of 50 cents - but not only the location, the environment is considerably more sophiscated. Dimly lit by candles in wrought iron sconces, the long, narrow room contrasts dark beams and whitewashed walls, dark wood floor and yellow tablecloths. Decorations are simple - sailing ships and copper utensils on the walls between the barn siding panels, banquettes lined with empty wine bottles, a homey touch of floral cushions tied to the chairs. A guitarist wanders among the tables singing, and welcoming people to join him.

The kitchen may be slow on a crowded night, and the waiters in their rush clatter dishes onto the busboys' stands, but they are expert and cheerful, behave as professionally as they look in dark vests and ruffed shirts. But it is only the waiters that are formal; the diners dress comfortably, bring the family on Sunday, bring high spirits on Saturday night, sometimes are moved to sing or dance. And celebrate the birth of a new El Caribe.